Recording apparatus



Oct. 16, 1962 W. HOFFMANN RECORDING APPARATUS l4 SheetsSheet 1 FiledNov. 25, 1959 INVENTOR WALTER HOFFMANN AGENT Oct. 16, 1962 Filed NOV.25, 1959 14 SheetsSheet 2 Oct. 16, 1962 w. HOFFMANN 3,058,415

RECORDING APPARATUS Filed Nov. 25, 1959 14 Sheets-Sheet s L L-J I q L Ul 1 /MK',; K FIGA K K: M A

, L -4 I FIG FIGAb Oct. 16, 1962 w. HOFFMANN 3,058,415

RECORDING APPARATUS Filed Nov. 25, 1959 14 Sheets-Sheet 4 Oct. 16, 1962w. HOFFMANN RECORDING APPARATUS Filed Nov. 25, 1959 14 Sheets-Sheet s 1Oct. 16, 1962 w. HOFFMANN 3,058,415

RECORDING APPARATUS Filed Nov. 25, 1959 14 Sheets-Sheet 9 A I 2 LL 1 29' A. Ag LL u. 5

Oct. 16, 1962 HOFFMANN 3,058,415

RECORDING APPARATUS Filed Nov. 25, 1959 14 Sheets-Sheet 1O Oct. 16, 1962w. HOFFMANN RECORDING APPARATUS l4 Sheets-Sheet 11 Filed Nov. 25, 1959Oct 16, 1962 w. HOFFMANN 3,058,415

RECORDING APPARATUS Filed Nov. 25, 1959 14 Sheets-Sheet 12 FIG. 9

Oct. 16, 1962 w. HOFFMANN RECORDING APPARATUS l4 Sheets-Sheet 13 FiledNOV. 25, 1959 Oct. 16, 1962 w. HOFFMANN RECORDING APPARATUS l4Sheets-Sheet 14 Filed Nov. 25, 1959 FIG."

United States Patent 3,053,415 RECORDING APPARATUS Walter Hclfmann,Adliswil, Zurich, Switzerland, assiguor to international BusinessMachines Corporation, New

York, N.Y., a corporation of New York Filed Nov. 25, 1959, Ser. No.855,452 Claims priority, application Switzerland Dec. 1, 1958 5 @iaims.(Ci. 10193 This invention relates to recording apparatus and moreparticularly recording apparatus of the record-controlled type forproducing permanent visual records of alphabetic, numeric, or specialcharacters upon a record receiving medium.

Numerical, alphabetical and special characters or marks which arehandled in coded form in digital computing devices or, more general, ininformation-processing machines, in most cases, must be recorded inreadable form for the operator, when the information-handling process isfinished. For this purpose, printing devices are, for instance, in use,which are called one-line at a time printing systems. A well knownone-line at a time printer is the wheel and hammer printer. This printeroperates in that the symbols to be printed are secured in the form ofletter and number types to the circumference of a rotating type wheel.The type wheel has as many lines of letter and number types as there areprovided difierent alphanumerical characters or symbols. Each line ofthe type wheel contains symbols of the same type only. Paper to beprinted upon, together with the ribbon, is passed through one-lineprinting positions. At each one-line printing position, a set ofindividually movable hammers are employed which are arranged along asingle line. The hammers can be selectively operated to strike againstthe paper, the ribbon and the type wheel.

It is a disadvantage of the one-line at a time wheel and hammer printersas used at present that for every line to be printed the type wheel hasto make a complete revolution, since only in that manner can all thedifferent symbols around the periphery of the type wheel be reviewd todetermine which of them is required for printing in the distinctposition of the printing line. Hence another disadvantage is thatcontinuous paper feeding is not possible. The paper record sheet mustalways be stopped in printing position during each revolution of thetype wheel. The speed, which can be achieved at present withalphanumerical one-line at a time wheel and hammer printers, is betweenand printing lines per second. If, for example, a line contains 120printing positions, the maximum achievable output speed is between 1200and 1800 characters per second.

The present invention overcomes the above disadvantages because there isno stopping of the record sheet during printing of individual lines andprinting takes place simultaneously on several lines.

t is therefore an object of the present invention to provide a recordingdevice in which the record medium is continuously movable, that is arecording device where the record medium is not started and stopped forthe printing of each individual line.

It is a further object of the present invention to provide a recordingdevice in which, as compared with the printers known in the art, themechanical parts are operated at uniform velocity and thus the wear ofthe mechanical parts is not increased.

A further object of the instant invention is to provide a recordingapparatus wherein both the individual character recording elements andthe record-receiving member are continuously moved at uniform butdifferent velocities so that each different character recording elementis presented to each of predetermined given areas of therecord-receiving medium.

An even further object of the instant invention is to achieve theforegoing object by providing an apparatus wherein the record-receivingmedium and the character recording elements move in the same directionbut wherein the velocity of the character elements is greater than thatof the record-receiving medium.

Yet another object is to provide a recording apparatus wherein therelative motion between the character recording elements and the recordreceiving medium is orthogonal and is so arranged that each differentcharacter recording element is presented to each of predetermined givenareas of the record-receiving medium.

Another object of the invention is to provide a record ing apparatuswherein a plurality of different matrical arrays of record producingelements is successively aligned with a plurality of different matricalarrays of discrete record receiving areas of a record medium and amatrix of record transfixing means is actuated by a timing means whichenergizes the individual elements constituting the matrix so as totransfix a given record in a given discrete area under control of codedinput data.

A supplementary object is to provide a recording apparatus in accordancewith the preceding object wherein both the matrical arrays of recordproducing elements and the record receiving medium are both in uniformmotion and the record transfixing is achieved when a given recordelement is aligned with a given discrete record area.

An additional object of the invention is to provide a recordingapparatus having a constantly moving recordreceiving medium and aconstantly moving array of different record producing elements, whereincodal input data manifestive of a line of data characters to betransfixed on a given line of said record receiving medium is recordedon a moving record medium upon which is permanently recorded asuccession of codal data manifestive of each different record producingelement in said array arranged in the same order, the said record mediumbeing movable synchronously with said record-receiving medium past anarray of codal receiving elements which detect both the coded input dataand the coded character data and upon a comparison thereof effect atransfixation of a character upon the record medium.

The printing device according to this invention comprises a recordmedium to receive a printed information and an arrangement of printcharacters having a given number of dilferent symbols. The printcharacters are arranged in sets, each set including one of each of saiddifferent symbols. There is provided according to the invention adriving means to continuously move said record medium with respect toand across a two-dimensional array comprising at least a part of saidprint characters of said arrangement and such that a plurality of printlines thereof simultaneously are located opposite and in close proximityto the print characters of said array and wherein said sets are disposedin such a manner that there is offered to each print position of saidplurality of print lines during their passage alongside said array eachof said different symbols a single time, there being provided for theprint characters of said array a print effecting means which enablesselective printing of the print characters.

The foregoing and other objects, features and advantages of theinvention will be apparent from the following more particulardescription of preferred embodiments of the invention, as illustrated inthe accompanying drawings.

In the drawings:

FIGURE 1 is a perspective view of the general type of a multi-line at atime wheel and hammer printer according to the present invention.

FIGURE 2 shows the differential drive mechanism to achieve a speed ratioof 1:2.

' part of the type wheel.

FIGURE 3 shows the distribution of the twenty number type lines acrossthe periphery of the type wheel.

FIGURE 4, which consists of FIGURE 4a and FIG- URE 4b, shows the wiringdiagram and a more detailed representation of the printer of FIGURE 1.

FIGURE 5, consisting of FIGURES 5a, 5b and 5c, and FIGURE 6 show timingdiagrams.

FIGURES 7a and 7b comprise a perspective view of another embodiment of aprinter according to the present invention.

FIGURES 8 and 9 are timing diagrams serving to explain the operation ofthe printer of FIGURE 7.

FIGURE 10 shows a perspective view of the printer section of anotherembodiment of the present invention.

FIGURE 11 shows the circuit of a coincidence device which may beemployed in the examples described.

Referring to FIGURE 1, a high-speed printer of the wheel and hammer typeis shown. The printer comprises a rotating type wheel 6 and two paperadvancing drums 2. The type wheel 6 rotates twice as fast as the paperadvancing drums 2; both rotate counterclockwise as indicated. The drivemechanism through which the desired rotational speed relation of 1:2 isachieved will be described later with reference to FIGURE 2.

A drum 9 with a magnetizable surface is connected to the paper advancingor feeding drums 2 by means of a shaft 8 which is driven continuously bya motor, not shown. The magnetic drum 9 and the paper advancing drums 2have the same rotational speed.

A paper record sheet 1 is fed around one-half of the surface of the typewheel 6 by means of guiding rolls 3 and the two paper advancing drums 2,the latter comprising a plurality of sprocket teeth 5. These teeth 5grasp through carriage holes 4 placed along both sides of the recordsheet 1. By this means, the record sheet 1 is advanced with theperipheral speed of the paper advancing drums 2.

For ease of understanding, only the ten numerical symbols 0 through 9are assumed to be provided in the disclosed printing system, but thisinvention is not limited to this specific case, and it is believed to beobvious to the person skilled in the art to design alphanumerical orother printers with any desired number of difierent printing symbols onthe bases of what is disclosed in the present description.

Referring again to FIGURE 1, the rotating type wheel 6 comprises, in theform of character type lines 7, a twodimensional array of numericalsymbols for printing. The single type lines extend axially across thecylindrical Each line contains type characters of the same kind only. Ineach line as many single character types are provided as desired printpositions in the printing lines. In the printing system presentlydescribed twenty character lines 7 are distributed in equidistant spacesacross the surface of the type wheel. Thus, the type wheel alwayscontains two lines 7 of each of the ten numerical symbols 0 through 9 inopposite positions. In FIGURE 3, the distribution of the twenty numbertype lines across the circumference of the type wheel is shown.

Ten lines of print hammer sets A through I containing individuallyselectable print hammers H are fixed in equidistant spaces along thelower half of the circumference of the type wheel. In each of the tenhammer sets A through I as many hammers as there are printing positionsin a printing line have to be provided. Generally, this number will bemarked with the symbol v and the hammers will be individually markedwith H through H H through H H through H H through H H through H Hthrough H H through H H through H H through H and H through H Altogether10 times 11 single hammers are to be pro- 7 vided.

Consecutive hammers H through H; are always positioned in spaces ofalternate print lines. Thus, nineteen consecutive print lines of therecord sheet are located between the ten hammer print positions Athrough I along the lower half of the circumference of the type wheel 6.This arrangement has the advantage that the positioning of theconsecutive hammer sets can be made twice as wide as is the distancebetween adjacent printing lines actually achieved on the record sheet.If a strike sensitive record sheet is used, no feeding of a ribbon isnecessary. If a common paper sheet is used, an inked ribbon sheet mustbe provided. Such an inked ribbon sheet is not shown in FIGURE 1. Itcould, for instance, be arranged between the paper record sheet and therotating type wheel 6 and might be moved in a similar way as is therecord sheet.

The magnetic drum 9, which rotates counterclockwise with the samerotational speed as the paper advancing drums 2, is divided, in axialdirection, into two sections. Referring also to FIGURE 4, andparticularly to FIG- URE 4b, the first section 10 contains fortymagnetic code markings in equidistant spaces around its cylindrical partof the surface. These forty code markings are composed of four times tendifferent markings which are or correspond to the ten number symbols 0through 9 of the type wheel 6 and which serve for the location detectionof the character lines '7 (FIGURE 1) of said type wheel 6. The sequenceof the code markings of the surface of section 10 must correspond to thesequence of the symbols of the character lines 7 of the type wheel 6that is the numbers 0 through 9 consecutively. Ten magnetic readingheads N through N forming line location detecting devices, are placed inequidistant spaces across one quarter of the periphery of section 10.Thus, the distance between two of these reading heads N is equal to thedistance between two code markings of section 10. Since the same kind ofcode marking is present four times on the drum surface 10, the codemarkings of the same kind are spaced degrees apart, and it is obviousthat the group of heads N through N in order to avoid tied package,could also be distributed around the whole circumference provided thattheir angular relationship to the respective code markings would remainunchanged.

The second section 11 of the magnetic drum 9 contains the information tobe printed in the same code used for the code markings of section 10.The information to be printed will be Written onto the magnetic drum 11consecutively line by line by means of a set of single magnetic writingheads 12, the magnetic drum section 11 serving as an information storagedevice. The distance between two information lines of section 11 will bethe same as the distance between two code markings of section 10. Theinformation passes consecutively line by line ten sets of magneticreading heads M through M which are placed in equidistant spaces acrossone half of the periphery of section 11. (In the perspective view ofFIGURE 1, the sets M to M of the information reading heads cannot beseen.) Thus, the distance between two information reading heads M istwice as large as is the distance between two consecutive magneticreading heads N. Single magnetic reading heads of section 11 are markedin accordance with the markings of the single hammers H, for example Mthrough M M through M M through M There are as many reading heads M inone information reading line as there are printing positions in oneline. This number has been defined with the symol 11.

When an information line has passed all ten reading stations M throughM;, the information will be erased by means of a set of erasing heads 13or by a single erasing magnet. Thus, after passing erasing station 13,the lines are ready to obtain new information. It should be noted thatcorrect alignment between the line indications of section 10 and theinformation lines of section 11 is of importance for reliable andcorrect operation of the printer. It is obvious that changes in thearrangement of the magnetic heads 12, 13, N through N M through MJ andin other parts of the system can be made. For

example, the magnetic heads could be arranged in helical form across thewhole periphery of the drum 9.

Reference is now made to FIGURE 2 which is a schematic diagram of thedifferential drive mechanism by means of which the desired rotationalspeed relation of 1:2 is achieved, which is necessary for driving thetype wheel 6 twice as fast as the paper advancing drums 2. For thispurpose, a differential mechanism is provided on the left side of thetype wheel 6 as shown in FIGURE 2. Instead of an outside bevel gear,merely a toothed wheel ring 14 is used which is mounted fixed and doesnot rotate. The inside bevel gear 15 which has a hollow axis is rigidlyfixed to the type wheel 6 which is loosely disposed on the driving shaft8 by means of ball bearings 17. This driving shaft 8 is connected to thepinion gears 16 of the differential onto which the paper advancing drums2 are mounted. Thus, the driving shaft 8 rotates the paper advancingdrums 2 with the rotational speed which is derived from a motor 18,whereas the rotating speed of the type wheel 6 is twice as fast becauseit is driven by the bevel gears 15 which rotate, as is obvious, withdouble the speed of the driving shaft 8. The right end of this drivingshaft 8 is connected directly to the magnetic drum 9 which rotates withthe same rotational speed as the paper advancing drums 2.

FIGURE 3 shows the distribution of the twenty number type lines (marked7 in FIGURES 1 and 3) across the periphery of the type wheel 6. Lineswith equal characters are, with respect to the axis opposite to eachother on the periphery.

FIGURE 4, which is divided into FIGURES 4a and 4b as shown, representsthe wiring diagram for two columns, designated 1 and 4 of printingpositions from which a complete comprehension of the whole Wiring schemeis possible. A schematic view of the printer system is shown in FIGURE4a. This printing system comprises the type wheel 6 with the marked typecharacters, the two paper guiding rolls 3, the paper record sheet 1 onwhich the single printing lines are marked with a, b, c, etc.

Across one half of the circumference of the type wheel 6, ten lines ofprint hammers H through H; are provided for ten positions of printinglines. In FIGURE 4a, only a fraction of all the hammers in each line isshown, for example, in printing line position I, the two hammers H} andH For the printing process, each print line of the record sheet 1 can beconsidered to be subdivided into individual print positionscorresponding to the individual print characters or hammer positions.Each such print position defines the space which may receive the printof a single character. Actuating means L (for instance solenoids) belongto each of these hammers H. They are designated with index numbers inthe same Way as the hammers themselves. These actuating means L areconnected through wires LK to corresponding coincidence devices K (FIG.4b) which comprise electronic circuitry for comparing the signals readby corresponding reading heads M and N. Here the same index designationis also used. Upon coincidence, in a coincidence device K, an actuatingsignal is sent through the corresponding output wire LK to thecorresponding actuating means L which operates the hammer H belonging toit.

FIG. 4b shows two columns (designated 1 and 4) of magnetic drum section11 with the magnetic writing heads 12 12 erasing heads 13 13 and readingheads M through M and M through M which are connected by wires MK to MK;and MK to MK respectively to the first inputs of related coincidencedevices K. The second inputs of the coincidence devices K are connectedthrough wires NK to the magnetic reading heads N which are arranged withthe magnetic drum section 10 containing the type character indicationcode markings.

It is obvious in which way the wiring system has to be extended for theother columns. In order not to overload the FIG. 4 with connections,that is for the sake of clarity, the two columns 1 and 4 have been shownonly. The operation of the described printing system may be bestunderstood by an explanation in which only one column position isdiscussed. The following designations 5 shall be used: The twenty typewheel characters are marked with 1', 2', 3', 4', 5', 6', 7, 8', 9, 0+,1+, 2+, 3+, 4+, 5+, 6+, 7+, 8+ 9+. For the purpose of the presentexplanation, the ten hammers are designated with H through H The tenmagnetic heads which sense the reference code markings of magnetic drumsection It are designated N through N The ten magnetic heads which senseinformation to be printed and which are arranged with the magnetic drumsection 11 are designated M through M The hammers and heads may forinstance be those of the first column from left.

For the timing schedule the individual steps are desig nated with (1),(2), (3), etc. We assume in our example that, for instance, thefollowing number pattern shall be printed in the first column from left.The pattern and the printing lines are coordinated as follows:

Pattern: 46855971102805126307 Line: tsrqpourulkjlhgfedcba Direction ofadvance The time interval during which the magnetic drum 9 rotates oneturn is divided into forty cycle units (time positions). During onecycle unit each point of the magnetic drum section 10 moves a pathlength which is equal to the distance between two adjacent reading headsout of the group designated by N through N It should be noted that,since the circumferential distance of the heads belonging to the group Mthrough M; is twice the distance of the N-heads, it takes two cycleunits Lia point of the drum section 11 to move from one head to theadjacent one. Two cycle units are necessary until a printing line of therecord sheet 1 has moved from one to the next hammer position. In onecycle unit the type characters 7 of the type wheel 6 reach the nexthammer position.

Now, for the first five time positions or cycle units,

the operation of the printer system will be analyzed in detail.

Time position (1): We suppose that at time position (1) the arrangementof the printer system is as follows:

Magnetic drum section 10: N is assumed to sense-0.

Magnetic drum section 11: M senses the first number of our pattern, thatis 7.

Printer: Opposite H is the first printing line a, and the type character0, as shown in FIGURE 4a.

The code marks sensed by the heads N and M produce signals representing'0 and 7 respectively which are fed to the coincidence device K Result:There is no coincidence between 0 and 7,

thus, H will not be actuated.

Time position (2):

Section 10: N senses 1; N senses 0.

Section "11: M senses the second number of our pattern, that is 0; thefirst number 7 is now positioned between M and M Printer: Opposite H isthe second printing line b,

and the type character 1.

Result: No coincidence between 1 and 0, no hammer actuated.

Time position (3):

Section 10: N senses 2; N senses 1; N senses 0 Section 11: M senses 3; Msenses 7; (the first number of our pattern has now reached the nextreading head M Printer:

H {is next to type 2 is next to line 0 is next to type 1 in next tolinea Result: No coincidence between 2 and 3 or 1 and 7,

no hammer actuated.

"2'' Time position (4):

Section 10: N senses 3; N senses 2; N senses 1; N senses 7 Section 11: Msenses 6; M senses 0; Printer:

is next to type 3 is next to line d is next to type 2 {is next to line bResult: No coincidence between 3 and 6 or 2 and 0,

no hammer actuated. Time position Section N senses 4; N senses 3; Nsenses 2;

N senses 1; N senses 0; Section 11: M senses 2; M senses 3; N senses 7;Printer:

is next to type 3 iis next to line 0 {is next to type 2 is next to linea Result: Coincidence between N and M therefore the correspondingcoincidence device K causes hammer H to be actuated and to print thetype character 3 onto line 0 of the record sheet.

Reference is now made to the enclosed timing diagram of FIGURES 5a, 5band 50 which show the printer operation not only for the first five timepositions described above but during the whole printing process for ourpro- 0 posed pattern, which will be completely printed during a maximumof forty cycle units. During these forty cycle units the type wheel 6makes two complete revolutions whereby 20 lines are printed.

For reasons of simplicity, we omit the designations M, N, and H in thetiming diagram and define the positioning of the various elements byposition letters A through I only.

In FIGURES 5a, 5b and Sc, which are to be taken together as shown inFIGURE 5, there are put down horizontally locations which are defined bythe hammer position. Vertically there are put down the time positions.Of each group of three lines belonging to each time position the firstline definies the type location with reference to the hammer position,the second line shows the pattern to be printed in its relation to thehammer positions, which may best be derived via their relation to thereading heads M, and'the third line indicates the positions of the linesa, b, c, of the record sheet 1 with regard to the hammer locations.

The types 7 (FIGURE 1), represented in FIGURE 5 by the numbers 0+, 9,8-, on account of the higher angular speed of the wheel 6, move fromleft to right twice as fast as the characters 3,. 0, 7, of the patternand the lines a, b, c, of the record sheet 1. The first occuringcoincidence is at time position (5). Coincidence is generally indicatedby a circle around the letter designating the record sheet linereceiving a print.

The hammers which perform the printing of the twenty lines and the timepositions where such printing takes place are the following:

Line (i0) 31) (is) he do (is (is) at timeosition 5 byharniiier H J B D IG d D A. D

Line I: l m n o p q r s t at time-position (11) (12) (31) (22) (16) (30)(3D) (30) by hammer A A J E F A I G I F According to the diagram ofFIGURE 6, there are plotted along the abscissa the time elements andalong the ordinate the hammer positions. The movement of the recordsheet 1 (in FIGURES 1 and 4) is represented by the lines a, b, c, andthe movement of the types 7 (in FIGURE 1) is represented by the lines9+, 0', 1, 2'. In accordance with the fact that the rotational speed ofthe types is twice the rotational speed of the feeding drums 2 (ofFIGURE 1), the lines 9+, 1', 2',

Time position: (5) (9) (I0) (11) (12) (14) (15) (16) B AX D A A D H A,D

Hammer:

Time position: Hammer:

Referring to FIGURE 7, which comprises FIGURES 7a and 7b as shown,represents a schematic view of another embodiment of a high-speedprinter. A plurality of print types are simultaneously advanced andcarry chains 21 which are driven in the direction as indicated by thearrow by means of wheels 22 fixed to driving shafts 23. Adjacent tothese type chains 21 there are provided a plurality of individuallyoperable hammers H, such hammers H being employed in as many lines asthere are provided type chains 21. The hammers H cooperate with the typecharacters during the printing process. The record paper 24, which iscontinuously fed upwards, moves between the type chains 21 and thehammers H. A ribbon, not shown in FIGURE 7a, will usually be placedbetween the types 21 and the record paper 24. A platen 25 is provided toform a backing to stop the movement of the striking hammers. It ispositioned on the other side of the type characters 21 than are thehammers H.

The movable type chains 21 comprises the characters or symbols to beprinted in the form of extending print types. Each chain or linecontains several sets of the total number of different charactersprovided. All chains contain the print types in the same consecutiveorder and arranged such that each column contains one kind of typesonly.

The use of type chains instead of a type wheel means that the recordpaper 24 does not have to be arranged partially surrounding theperiphery of the type wheels as this is the case in the foregoingexample, but can be advanced in a plane situated between the type chains21 and the print hammers H.

For better understanding against only the ten numerical symbols orcharacters 0 through 9 are provided in this example of the printingsystem. However, the present invention is not limited to this specificcase, and it is possible to build alphanumerical or other printers withany desired number of different printing symbols according ot theprinciple of the invention.

Referring again to FIGURE 7a, the number of type chains is equal to thenumber of different kind of print characters provided, and for eachprint character there is provided a corresponding hammer. Thus, in ourcase, for the ten different numerical characters 0 through 9 there areten lines of type chains and ten lines of related hammer sets. Theselines shall be indexed A through .I. In each of the ten hammer sets,there have to be provided as many individually selectable hammers asthere are printing positions in a printing line. Generally, this numberwill be marked with the symbol 1 and the hammers will be individuallymarked with H through H I-I through H and so forth to H through HAltogether 10 times v single hammers are provided. An actuating means L(i.e. a solenoid or the like) belongs to each of these hammers H. Theactuating means L are designated with index numbers in the same way asthe hammers themselves. They are connected through wires LK tocoincidence devices K shown in FIGURE 7b.

Reference is now made to FIGURE 7b. The upper part of this figure givesa schematic view of a magnetic drum 9 which rotates counter-clockwisewith a rotational speed in a certain relation to the rotational speed ofthe type chain moving wheels 2 (FIGURE 111) as will be outlined later.This magnetic drum is divided into two sections 10 and 11.

The first section 10 contains a plurality of magnetic (1 (21) 1) o J r EEl no 1,1

reference code markings in equidistant spaces along its surface. Thesemagnetic reference code markings are composed of diiferent markingswhich are indicative of the different print character locations of thetype chains. In the printer system as shown, two sets of ten differentmagnetic reference code markings are provided which correspond to theten columns of number symbols through 9. The sequence of the magneticreference code markings on the surface of the magnetic drum section 10must be the same as the sequence of the print characters of the typechains 21, namely 0 through 9 consecutively.

Ten magnetic reading heads N through N are placed at equal distancesacross one half the periphery of the magnetic drum section 10. Thedistance between adjacent reading heads N is equal to the distancebetween adjacent print character location indications on the magneticdrum section 10.

Generally, there must be at least as many reading heads N as there aredifferent kind of print character columns. If, however, the number ofcolumns of the record sheet 24 is higher than the total number ofdifferent kind of print characters, some or all of the reading heads Nare related to more than one column of printing. For example, if thenumber of columns of the record sheet 24 is three times the number ofdifferent kind of print characters, then each reading head N isallocated to three columns of the record sheet 24. Should the number ofprint columns be less than the number of different type characters(which is unusual), then no more reading heads N are necessary than isthe number of print columns.

The second section 11 of the magnetic drum contains the information tobe printed in the same code as is the code used for the reference codemarkings or print character location indications of section 10. Theinformation to be printed will be written onto the magnetic drumconsecutively line by line by means of a set of magnetic writing headsW. In FIGURE 7b, there are shown the heads W and W The distance betweenadjacent information lines of section 11 will be the same as thedistance between adjacent reference code markings of section 10. Theinformation passes consecutively line by line ten sets of magneticreading heads M through MJ which heads are placed at equal distancesacross one half of the periphery of section '11. The distance betweentwo adjacent liues of information reading heads M is the same as thedistance between two adjacent character location indication readingheads N.

The single information reading heads M of drum section 11 correspond ina certain way to the print hammers H. Thus, they are marked inaccordance with the designations of the single hammers H, for example Mthrough M M through M and so forth to M5 through My. There are as manyinformation reading heads M arranged in one line as there are printingpositions provided in one line of hammers H. Generally, we have definedthis number with the symbol 11.

When an information line has passed all ten reading stations M through Mthe information will be erased by means of a set of erasing heads E.After erasing, new information can be written by means of writing headsW. It should be noted that correct alignment between the reference codemarkings of section and the information lines of section 11 is of greatimportance for a reliable and correct operation of the printer.

Reference is now made to the wiring scheme (FIG- URES 7a and 7b).Although, for the sake of simplicity, the wiring scheme is given onlyfor two columns (designated l and 4) of printing positions, a completecomprehension of the Whole wiring scheme will easily be possible. Themagnetic heads M (M and M are connected by means of wires MK (MK; andMK;*) to the first inputs of related coincidence devices K (K; and K5the functioning of which will be explained later. The second inputs ofthese coincidence devices K are connected through wires NK to themagnetic reading heads N arranged around the magnetic drum section 10containing print character location indications. The output terminals ofthe coincidence devices K are connected through wires LK to the relatedhammer actuating means L. The same index designation as used for thehammer actuating means L and the magnetic heads M, respectively, is alsoutilized for the coincidence devices K and for the wire connections MK,NK and LK.

It is believed to be obvious in which way the wiring has to be extendedfor the columns other than the columns l and 4 as shown in FIGURES 7aand 7b and therefore these connections are not shown in detail.

The operation of the disclosed printer system will best be understood byalso referring to FIGURES 8 and 9, which show operational timingdiagrams in graphical form. Also here, for reasons of simplicity, thetwo column positions 1 and 4 will be discussed only. The ten hammersconsidered are H to HR of the first column and the ten hammers of thefourth column designated with H through H The magnetic heads which sensethe character location indication markings of magnetic drum section 10are N and N The magnetic information reading heads of magnetic drumsection 11 are M through M and M through M The printing lines of therecord sheet and the information lines of magnetic drum section 11 aredesignated with a, b, c, etc. The operational cycle units (timeposition) are again designated with (1), (2), (3), etc. The typecharacters which pass the print positions in a consecutive order are 0through 9, lower values first.

We consider in this example that, again, the following number patternshall be printed in the first as well as in the fourth column. Thispattern is related to the information lines of drum section 11 and tothe printing lines of the record sheet as follows:

Pattern: 4

Direction of advance The time interval during which the magnetic drum 9rotates one turn is divided into twenty cycle units (time positions).During one cycle unit, each point of the magnetic drum sections 10 and11 moves a path length corresponding to the distance between twoadjacent reading heads M or N. During one cycle unit, a printing line ofthe record sheet 24, which is moved continuously upwards, will alwaysreach the next hammer position and again in one cycle unit, each typecharacter of the type chains 1 continuously moves from left to right andwill reach the next hammer position. The interconnection of the typechain driving shafts 23 (FIGURE 7a) with the driving means of the recordsheet and the magnetic drum respectively (not shown), is deter-mined bythis timing schedule.

The graphical timing diagrams FIGS. 8 and 9 give a time sequentialpresentation of the operation of the Whole printer system for the first(FIG. 8) and fourth (FIG. 9) prlnt columns. In both figures, along theabscissa there are plotted the cycle units (time positions), whereas theordinate represents the positions of magnetic heads M to M and N of thehammers H to H9, respectively. The vertical lines represent both theprint character indications on drum section 10 and evidently, the typecharacters. The diagonal lines represent the information lines of drumsection 11 and also the printing lines of the record sheet.

To explain the operation of the printer with reference to therepresentation of FIG. 8, the time position (10) may be considered. Atthis instant, the type characters 9 are at the location of the hammer HAt the location of hammer H is the line j of the record sheet 24, ofhammer H is the line i of the record sheet 24 and so forth and at thelocation of hammer H is the line a. Also at this time position (10) thehead M is reading line i of the information drum 11, head M is readingline i of the information drum 11 and head MJ is reading the informationline a on the drum 11. Points of intersection of the lines indicatewhich print character location indications are associated with thevarious information lines of drum section 11 at distinct time positions.

They also indicate which type characters are associated at theparticular time positions with the various printing lines of the recordsheet. The particular points of mtersections at which coincidence occursbetween the code markings read by corresponding magnetic beads M and Nare marked by small circles. The information pattern is assumed to bethe same for the print column 1 as for the print column 4. The crosspoint markings represented by a small circle also indicated theactuation of the respective hammers by which printing is effected.

The operation of the various parts of the printer during the first fourtime positions (cycle units) will now be explained in detail withreference to FIGURES 8 and 9.

Time position (1): We suppose that at this time position, thearrangement of the printer system is as follows:

Magnetic drum section 10: N reads character location indication marking0, N reads location marking 7.

Magnetic drum section 11: M reads the first column position ofinformation line a which, according, to our pattern, contains 7. M readsthe fourth column position of information line a which, because the twopatterns are assumed to be identical, also contains a 7.

Printer:

type character 0, Opposite H is positioned [first print position of linea type character 7, Opposite H is positioned{fourth print position ofline a.

Result: There is no coincidence in column 1; coincidence, however,occurs in column 4 between N and M because both read code marking 7.Thus, hammer H is actuated which prints type character 7 into the fourthcolumn position of print line ,a.

Time position (2):

Drum section 10: N reads 1; N reads 8;

Drum section 11: M reads M reads 7; M

reads 0; M reads 7;

Printer:

Opposite H is line b and type 1 Opposite H is line a and type 1 OppositeH is line b and type 8 Opposite H is line a and type 8 Result: There isno coincidence in column 1 and no coincidence in column 4.

Time position (3): a

Drum section 10: N reads 2; N reads 9;

Drum section 11: M reads 3; M reads 0; M reads 7; M reads 3; M reads 0;M5 reads 7;

Printer:

Opposite H is type 2 and line c; Opposite H is type 2 and line b;Opposite H is type 2 and line a; Opposite H is type 9 and line 0;Opposite H is type 9 and line b; Opposite H is type 9 and line a;

Result: There is no coincidence in column 1 and no coincidence in column4.

Time position (4):

Drum section 10: N reads 3', N reads 0;

Drum section 11: M reads 6; M reads 3; M reads 0; M reads 7; M reads 6;M reads 3; M reads 0; M reads 7;

Printer: 2

Opposite H is type 3 and line d; Opposite H is type 3 and line c;Opposite H is type 3 and line b; Opposite H is type 3 and line a;Opposite H is type 0 and line d; Opposite H is type 0 and line c;Opposite H is type 0 and line b; Opposite H is type 0 and line a;

Result: There is coincidence in column 1 between N and M Thus, hammer His actuated and type character 3 is printed into the first columnposition of print line c. There is also coincidence in column 4 betweenN and M5 Thus,

hammer H is actuated and type character 0 is printed into the fourthcolumn position of print line b.

The proposed pattern will be completely printed during a maximum ofthirty cycle units. During these thirty cycle units, the magnetic drum 9makes one and a half revolutions whereby all 20 lines are printed.

FIGURE 10 shows an example, according to which the print hammers H ofFIGURE 7 are replaced by flashable light sources 33 and the printcharacters 34 are made of a transparent material built into a movablecarrier 32 which is impervious to light. The belt like carrier 32 isdriven by the two drums 22 rotatable around their axis 23, respectively.The record sheet 31 is movable in the upward direction as indicated bythe arrow and is provided with a light sensitive material on the surfacevisible in the FIGURE 10. The part of the printer comprising themagnetic drum, the magnetic heads, the coincidence devices and thewiring associated therewith may be identical to the circuit arrangementin FIGURE 7b. The connection of the wires LK is the same as in theexample of FIGURE 7, so that the arrangement of FIGURE 7b and FIGURE 10may be considered to be connected together at the place of thedashdotted lines. Thus, upon a signal from, for instance, thecoincidence device K a signal is transmitted through the wire LK whichsignal operates an actuating device that causes the light source towhich it is connected to emit a light flash. This light flash penetratesthrough the transparent character symbol at the location of the lightsource and causes the character symbol to be printed on the record sheet31. The light sensitive surface thereof is for instance a photographicfilm. In another performance, the record medium may be a carrier of thecharge pattern in a Xerographic printing process.

The coincidence devices K, as this is mentioned in connection withFIGURE 4b and FIGURE 71:, may be any such device as are known in the arttoday. By way of example and for the sake of completeness of thedescription only, such a coincidence circuit will be described in thefollowing, whereby reference is made to FIGURE 11. The coincidencedevice is shown within the dotted lines. The device has an input NKleading from one of the print character location reading heads N to thewires 101-104, 106-109, and an input MK leading from one of theinformation reading heads M to the input wires 111-114, 116-119. Wire101 is connected to rectifier 135, wire 102 is connected to rectifier131 and so on, and wire 119 is connected to rectifier 122, as shown inFIGURE 11. The direction of low current resistance of the rectifiers121-136 is the direction of flow into the wires 1&1 to 104 and 106 to109, 111 to 114 and 116 to 119. The rectifiers 121 to 136 are connectedto the resistors 161 to 168 as follows: Rectifiers 121 and 122 toresistor 168, rectifiers 123 and 124 to resistor 167 and so forth andrectifiers and 136 to resistor 161 as this is shown in the FIGURE 11.The connection between the rectifiers 121 and 122 and resistor 168 isalso connected to rectifier 141, the connection of rectifiers 123 and124 with resistor 167 is also con-

